Hydraulic classifier and separating process



Nov. 22, 1927. 1,650,239

' F. W. SCHMIDT ET AL y HYDRAULIC CLASSIFIER AND SEPARATING PROCESSFiled Sept. 14. 1925 l 5 Sheets-Sheet 2 ATTORNEY Nov. 22, 1927.

` F. W. SCHMIDT ET AL HYDRAULIC CLASSIFIER AND SE'PARATING PRocEss 5sheets-sheet s Filed $6915.14, 1923 Wh INVENTORS, o?. I 4

ATTORNEY Nov. 22, 1927.y 1,650,239

F. W. SCHMIDT ET AL HYDRAULIC CIQASSIFIER"y AND SEPARATING PROCESSFi1eds'ept-14, 1923 5 sheets-sheet 4 Nov. 22, 1927. 1,650,239

, F. W. SCHMIDT ET AL Xymf,

ATTORNEY Patented 151mlaa'19272-I UNITED STATES v FREDERICK W.SCHMIDT'AND WILLIAM M. GREEN, OF MORRISTOWN, NEW JERSEY.

EYDBfAULIC GLASSIIFIER AND SEPABATING PROCESS.

Application illed September l14, 1923, Serial No. 662,624.

This invention relates to processes.` and apparatus for materialseparating and sorting, particularly for separating loam and sand Jfromgravel as .it occurs naturally in the well known gravel banks or glacialmoraines and also sorting the gravel and also the sand; and moreespecially for separating and sorting of the kind described accomplishedhydraulically.

A primary object `of this invention is to provide a process of thenature indicated whereby the various sizes@ of gravel in an ordinarygravel bank may be separated from sand and loam and may be sorted intoseveral different masses each containing bodies varying in size onlybetween Xed limits, which masses will contain bodies washedsubstantially clean and free from sand' an loamf.

A further object of'the invention is to provide a process whereby thesand and loam separated 'from the larger bodiesiof the gravel may besubstantially separated one from the other andthe sand separated intomasses of -substantially dierentrelative coarseness.' f

A further object ofthis invention is to provide a process of thev'nature indicated whereby gravity alone will act as the motive forceforthe mass of mixed loam, sand and gravel, after the masshas been onceelevated to the receiving station of the `apparatus which we havecontrived for carrying out our process, until the separated and sorted4material is actually delivered into vehicles for transporation to thepoint of use.

n*A urtherbbj'cct of this invention 4is the provision` of a,v process'"whereby a mobile liquid, such as water,- maybe employed as atransporting medium for the loam, sand and gravel to be separated andsorted,l so that as the gravel is transported it is freed from adheringloam and sand bythe washing action of the liquid aided by the constantcol,-

f lisions between the bodies or Stones makin-g` up the mass of thegravel, and the sliding and, rubbing ofthe stones on and against thedistributing tables forming a part of lthe apparatus selectedby 'us toillustrate the operation of ourl process.

A further object of. the invention is the provision of a process wherebyby using a mobile liquid, such as'water, as a transport ing medium, theinclination to thehorizontal of the successive dietrbutipg tablespresent in the apparatus which we have contrived to carry out ourprocess is less than would be necessary in dry sorting and the mainsorting screens at the lower end of each] successive table may be. ofsubstantially the same inclination as the tables, and the inclinationmay be such that the oversize material on a particular screen tends toaccumulate on that screen and so bewashed by the passing and splashingliquid and then gradually forced or pushed over the lower edge of thescreen.

A further object of the invention is the provision of a basin where thelight suspended matter in the liquid transporting medium after emergingfrom the process may be allowed to settle and leave the supernatant dliquid freel and-clear to be returned to the process. n

A further object of the invention is `the provision of a process wherebythe volume of liquid transporting medium used to elevate the mix'edmaterial to the receiving station may be conveniently decreased inamount at the receiving station, if too great in volume for the mass ofmaterial delivered, and at the same time any gravel and sand removed bydecreasing the volume of liquid transporting medium may be recovered andreturned to the process.

A further object o the invention is the provision of a process wherebythe liquid transporting 4medium is continually returned to the processafter being used. Other objects and advantages will appear as thedescription of the process and the particular physical embodiment ofapparatus selected illustrate the operation of the process, progresses,and the novel features of the invention will be particularly pointed outin the appended claims.

In describing the invention in detail, and

the particular physical embodiment of' apparatus lselected `toillustrate the operation of the process, reference /will be had to theaccompanying drawings wherein we have illustrated a preferred physicalembodiment of apparatus selected Ato illustrate the operation of theprocess and wherein like characters of reference designate correspondingparts throughout the several views, and in which:

Figure l, is a perspective viewillustrating the complete layout ingourprocess; Fig. 2, is a plan view of of a plant for practic` ing asorting structure proper, employed in carrying out our invention; Fig.3, is a longitudinal elevational cross sectional view of the structureas illustrated in Fig. 2; Fig. 4f, is a cross sectional elevational viewon the planes indicated by the line IV-IV of Fig. 3, viewed in thedirection of the arrows at the ends of the line; Fig. 5, is a crosssectional elevational view on the planes indicated by the line V-V ofFig. 3, viewed in the direction of the arrows at the ends of the line;Fig. 6, is an enlarged perspective detail of the arrangement andconstruc-l tion of apparatus at the receiving end of our i table sortingstructure.

A glacial moraine or gravel bank, is indicated at G in Fig. 1.- As iswell known to those skilled in this art, a gravel bank, as

ordinarily understood, is made up of particles or bodies varying in sizefrom very large boulders to extremely tine sand and in additionfrequently has a stratum of loam and usually a top covering of greaterorless thickness of earth or loam. For the purposes of description, inconnection with our ,invention, it will be assumed that the material tobe treated by our improved process consists of a mass composed of moreor less of vall of the above mentioned constituents.

It is well known to those skilled in the art,that at the present timethere exists a large demand for what is known as gravel and sand forforming the aggregate in concrete structures of many kinds. It is alsowell known that this sand and gravel is desired free lfrom loam and thegravel is demanded in masses,all ofthe bodies 'of such masses bein of asize that is above a. lower limit and low an upper limit and that thesemasses are desired in various grades,'that is, a mass is desired, forinstance, all of the bodies of which will pass through a screen havingtwo inch square openings therefn or round openings two andone quarterinchesin diameter therein and will not pass through-a screen having oneinch square openings therein or one: and onequarter inches inv diametercircular open- Jings therein. Such gravel would be known as one and onehalf inch gravel. There 1s, further, a demand for gravel known as threequarter inch gravel, which will pass through a screen having one inchsquare openmgs and will pass over `a screen havone half inch squareopenings. There is further what is known as onequarter lnch gravel whichwill pass through a screen havmg one half inch square openings therembut will pass 'over a screen having' one quarter inch s uare openingstherein. Material which wi pass through a screen having one quarter inchsquareopenings there- 1n 1s generally considered as sand, but for somepurposes, as. forhplasterers and brick yers mortar, it is necessary tohave sand which is freed from the larger particles which would passthrough a screen having one quarter inch square openings therein.Heretofore the sorting of the material of the usual gravel bankgenerally has been 7 accomplished by excavating material there-l in bythe use of various excavating implements and arrangements and thenelevating the same either before or after being put through crushers, tothe top of a struc- '7- ture of some considerable height. After be-l ingso elevated the material-is quite generally allowed to fall by gravitythrough a series of somewhat cylindrical revolving hollow screens, soarranged that the material which will not pass through the meshes of thefirst screen is delivered to the second screen and so on. The smallestmaterial passes through the meshesof the first screen and the largestbodies emerge from the last screen of the series. During the process,jets of water are directed on to the'materialso as to wash it free fromadhering'sand and loam. This process requires a very considerableexpenditure for constructing t-he plant initially and a further veryconsiderable expenditure for maintenance and for operation due to thegreat amount of power consumed in rotating the screens and the excessivedeterioration of the revolving screens and the mechanism between thescreens and the. prime mover furnishing the power. p Applicants purposeforming a cavity in the gravel' bank as G, Fig. l, of such depth thatground and-surface water as W may both accumulate. Upon thewater W isiioated a scow S having a suitable source vof motive power P positionedthereon and from this source of motive power, a shaft 1, extends to thecentrifugal or other suitable form of pump 2. The pump inlet isdesignated 3, and is a pipe of suitable size and suitably and.appropriately supported in a mannerwell known to those skilled in theart. and extending down through the water `Wto the'underlying gravelbank. The outlet or dischargev end of the `pump is designated 4, andcommunioatesfwith a pipe 5, supported in any desired or most appropriatemanner and extending to theV top of the sorting structure proper,designated as a Whole by T. Itis well understood by those skilled in theart that structures and arrangements comparable to that designated bynumerals 1 to 5, inclusive, and by letters P and S, are in use forpurposes such as dredging rivers and like bodies of water,

and applicants intend for such structure-tot?) l A iS sucked into `the`pipe-3 and discharged 130 into the pipe along with a quantity of watersullicient to Cfill the bore of the -pipe 5. In an actual installationmade by applicants, the pipe 5 has an internal bore of '12 inches andmay be caused to deliver thirty live hundred allons of water per minuteat its upper ischarge end. In an actual installation, applicants havearranged the pipe 5 from the point where it divergesfrom the" horizontalat an angle of 22% degrees to the horizontal.

In actual operation, the pipe 5 will be onnected to the discharge end 4by any suitable or appropriate means whereby considerable latitude ofmovement is allowed between the pipe 5, and pipe 4, as by a Hexible,connection or a iexlb-le pipe, so that the scow may have considerablemovement upwardly and downwardly vand sideways, without. putting anyconsiderable strain upon the pipe 5; such means needs no illustration asit is old and well known in the art of dredging and involves nothingmore or less than simple mechanical expedierts.

The operation of the pump 2 canbe made to wear away the gravel bank atany desired point .by merely directing the inlet 3 to the point which itis desired to wear away, `and in actual opera ifm, by suitablemanipulation of pipe 3 and by inserting suitable lengths of pipe 5 in te discharge end 4, the scow-inay advance over a very considerable rangeof. territory surrounding the structure T, always floating upon thewater which flows into the excavation which it has made itself.

As will be describedhereina-fter, in more detail, the water which isdelivered to the structure T together with the gravel material, issubstantially all returned to the Ipond or body of water upon which thescow oats so that the operation of the pump 2,does not 'result inexhausting the water even if that water is of a limited amount as itisbeinn constantly returned to the place from whic it was pumped. Themixed water and gravel material forced through the pipe 5 is deliveredto what we will term a receiving station designatecl byR and shown indetail in Fig. 6. By reference to Fig. 6, it will be seen that the -pipe5 is cut r it an angle-at its upper deivery end. 'This angle ma s cieinstallation as made by applicants,`1s that which mould be given bystarting )the bevel 10 vinches back from the end inthe case of a 12Vinch pipe which applicants actually use,l

thereby enabling the discharged material to p the bars of the grizzlydepends ent1rely upon sort of spread and fall more as a shower. Themixed gravel material and liquid medium or water, as'it is deliveredwith some considerable velocity from the pipe 5,*envcounterspthevgrizzly Z composed of bars somewhat T shaped'with the top of the Tpresented t0. the end of the plpe. These bars are parallel one to theother and have a clear two inch or other suitable space between thenearest points and are positioned so that .they are at an angle lessthan a right angle to the longitudinal center line of the pipe ,5, thatis, .the angle A, Fig. 6, is less than a right angle and in an actualinstallation made by applicants, it is about forty seven degrees. Theobject of placing the bars of the grizzly Z at an angle other than aright angle to the longitudinal center line of the ipe 5, is to preventas much as possible, tlie clogging of the grizzly Z by the deliveredmaterial. If this material were delivered normal to the Surface of theygrizzly Z andl with considerable force, then those irregular bodieswhich might partlyl enter the spaces between with great f ree betweenthose bars and the following n aterial would tend to drive the arrestedmaterial still more firmly between the bars of the ,grizzly,'but whenthe matethe bars would be driven rial is not delivered normal to thesurface .-of the grizzly, the material does notl have the same tendencyto clog the grizzly, and if any material does become temporarily lodgedbetween the barsof the grizzly, then the succeeding material tends tofree the arrested material as it is delivered not normal to the surfaceof the grizzly but at an angle thereto. such that the material tends toslide along the bars of the grizzly and SQ become free-d if it does notpass therethrough; The bars of the grizzly, as hereinbefore stated,

are not rectangular in cross sections but apl proximate somewhat toa Tin cross section except that the angles vbetween the vertical and thehorizontal limbs of the T may be considerechtol be filled into someextent, that 4is they are somewhat arrow shaped. This ,construction ofbar .has been selected so as to vfurther revent a clogging of thegrizzly Z. With t is construction of bar, if material succeedsv inpassing those portions which most closely approach the exit end ot pipe5, then its further progress is assured t'ecause it then enters a. spaceof greater dimansions and if a body does Amediately in passing the mostrestricted o ening between the bars, then it is swept a ong by thefollowing material down the face of the' grizzly and away a particularinstallation made by applicants, adjacent bars of I points are twoinches, apart because that iS the upper limit for the largest sizegravel which applicants desire` to obtain at that articular plant. 'Ofcourse 'the .spacing of the upper limit of size of the largest sizematerial which it is desired to sort. f

-Material. which does not pass through the `grizzly Z falls on to thescreen 6. This vma.- terial thus falling onto the vscreen 6, ma stallcontaln baches which w11l pass throug notsucceed imtherefrom. In

the grizzly at their nearest a screen having two inch square openingstherein so that it is allowed to roll by avity down the screen 6 to theend that it will CJI rial and to obtain every ton o r cubic yard ofmaterial possible from a given mass of elevated material, that is, ifthe upper limit of the material which is salable is that which will passthrough a screen having two inch square openings therein or through 'ascreen having circular openings two and one quarter inches in diameter,then the object is to i end thereof, in a bottom 11.

recover from the material delivered at the receiving station every laststone which by any possible means may bc made to pass freely througheither one of such screens and in considering this question, it must berelnembered that certain stones are so shaped that when delivered incertain ways on a screen having two inch square openings therein, theywill not pass therethrough but thed same stone may well pass through ascreen having circular openings twoand one quarter inches in diameter orvice versa, s'o that all material should be given every possible chancevto pass through a limit screen before being rejected to fall into whatmay be called the discard or oversize bin. Due to these considerations,applicants position a vertical screen 9 back of the grizzly Z whichscreen has circular openings therein, two and one quarter inches indiameter. The material which passes through the grizzly Z is allowed tostrike the screen 9 and pass therethrough if it will do so, but if itdoes not, it falls onto the upper end of the screen 6 and it mayimmediately pass therethrough, but if it does 'not immediately-passtherethrough, it rolls down the screen 6 and is arrestedat two pointstherein, once by baiile 7 .and again by baile 8, and not until then,does it fall over the exit end of screen 6. All material which rolls'oscreen 6, drops into a chute '10 which terminates, as best shown in Fig.3, at the upper left hand The material falling down the chute 10 landson the bot-4 tom 11, accumulates there so as to absorb the shock loffurther falling material and prevent too rapid deterioration ofthe,bottom 11,` and when suiliciently accumulated rolls` oft' on to thesloping deck 12, then ldown that deck onto thescreen 13, being arrestedin its motion by the -baliles 14,15 and 16. All mate- 4 .rialWhch'passes over screen 1,3,d'rop's into which has had every de lector17, and when suilicient material has accumulated therein, furthermaterial rolls oll onto screen 18, and is arrested in its downwardmovement by pivoted baffles 19, and 21. All material which passes overscreen 18 falls into chute 22 and from the chute 22 drops into thediscard bin 23. The material which passes through screen 18 dropsdirectly into the bin 24 which in the lation to which reference is beingmade throughout this specification, and by reason of the sizes ofscreens specified, may be con'- sidered to be the bin for the one andone half inch gravel. Material which passes through screen 13, dropsupon the receiving platform 25 also well shown in Fig. 4, in whichfigure may also be seen the sloping construction of receiving platform25 constructed to the end that all material which drops thereon willslide ofi' into the bin 24. From the hereinbefore given description,

actual` instalit will now be understood that the only matey rial whichgets into the discard bin 23 is that opportunity to pass through alimiting screen but has failed to do so, that is, it has had npportunityto pass through the screen 9 having circular openings therein, two andone quarter inches in diameter,it has had an opportunity to pass throughthe screen 6 having square openings thereintwo inches in diameter and ithas had an opportunity to pass through screens 13 and 18 each having twoinch squareopenings thereinj We desire to further point out that all of'the material which rolls down the screen 6 is not-f only retarded in atoo rapid descent. by the baftles 7 and-8, soas .to gain a betteropportunity to fall through the openings in the screen 6, but thismaterial being somewhat temporarily held at bailes 7 and 8 and thescreen 6 is by the water. issuing from pipe 5, quite thoroughly Washed`from all loam and sand adhering thereto so that the baiies 7 and 8 notonly serve to arrest the momentumof the material rolling down the screen6, to enable that material to gain a better opportunity to pass throughthe openings of the screen 6, but the baffles 7 and 8 also serve *115'to arrest the material so that it may be washed the more' thoroughly theliquid transporting medium or water flowing from the plpe 5 all to theend that the material which rolls over the exit end of screen 6 andwhich thereafter rolls over screens 13 and 18 and falls directly intothe bin. 24 may be entirely free from sand and loam andv all sand whichis delivered by pipe 5 will falll through screen 6 and none be carriedwith the discarded material to the discard bin 23, as it isobvious that'all sand which reaches the bin 23 is practically lost as a salablecommodity, that is, appllcants desire not onli to recover from the.material delivered from Pi e 5 @very laatsten? Whh maybe made passingsomewhat slowly over graded sand yand graded gravel and separatto passthrough. an upper limit screen, but also every grainof sand delivered bypipe and to recover that grain. of sand not mixed with discardedboulders but in its proper place together with the other grains of sand.

All material which passes through screens 9 and 6 falls upon the-table25 best shown perhaps in Fig. 3, and also in Fig. 4. All of thismaterial is below the upper limit of size and all is salable'excepttransporting medium or water, and the loam which may be mixed therewith.The further operations consist in separating this material deliveredonto the table into ing the water and loam therefrom.

In an actual installation, applicants have @found that screens 6, 13,and 18, function best at an angle of about forty-two and onehalf degreesto the'horizontal and screen 9 at an angle of ninety degrees orvertical.

The table 25 is nothorizontal but slopes downwardl7 to the right asviewed in Fig.

= 3, at a pitch of about one half inch to .the

foot, that is at a much less angle to the hori;v

zontal than the critical angle of flow of the dry material. All of thematerial dropped onto the left hand end of table 25', as viewed in Fig.3, is washed by the liquid transporting medium toward the right, thatis, to the lower end of the table and onto a screen 26 formingractically a continuation of the table. Allthough the wat-er upon thetable 25 may be several inches in depth and may appear to fiow withgreat rapidity, nevertheless, the quantity of water and the quantity ofmaterial is to be arranged in such proportions and the slope of table 25is to he such that the transported material must not practicallyinstantly pass over the screen 26, but the arrangements must besuch thatthe large material which does not pass through screen 26 will sort ofaccumulate on the lower portion, say the lower one half portion, of thescreen 26, and be gradually forced over the lower edge of screen 26 bythe impact of the following material, to the end, that all materialwhich does finally pass over the end of the screen 26 is thoroughlywashed by the splashing water of all adhering sand and loam and givenample opportunity to pass through screen 26 before being forced over thelower end of screen 26. From the material which passes over screen 26 isderived the mass which constitutes, what, for specific illustratiomwewill designate as `the one and one half inch gravel, so before thismaterial enters its proper bin. it is dry screened by screens 27 and 28to further insure proper sorting. splash board 30 is positioned justbeyond the lower end' of screen 26 so that any water which splashesbelow the lower end of screen 26 strikes the splash board 30 and is forvthe liquid :thus directed downwardly straight through the screen 27, sothat beyond the splash board 30, the material is not subjected towashing.

It is also true that screen 28 is in effect a dry 27 and 28. at an angleof 35 to 40 degrees l to the horizontal.

The material and liquid transporting medium passing through screens 26,27 and 28 falls upon the table 33 which like the table 25 is pitchedabout one half inch to the foot and terminates in the screen 34 whichhas a splash board 35 positioned just below its lower end and has thescreen 36 corresponding to screen 27 to receive material pushed over thelower end. of screen 34 and the screen 37 is positioned exactly like thescreen 28 to receive material from the screen 36. The material whichpasses over screens 34, 36 and 37 dropsinto the chute 38 and falls intothe bin 39. All material which falls into the binl 39 ,is what wedesignate three quarter inch' gravel, intermediate size gravel, or.specifically three quarter inch gravel, because screens 34, 36 and 37,are arranged and constructed and function exactly as do the screens 26,27 and 28, except that screen 34 has one half inch square openingstherein and the screens 36 and 37 have rectangular openings having atransverse dimension of one half inch and a dimension the other way ofthree quarters of an inch in an actually constructed plant.

All material passing through screens 34,.

36 and 37 falls upon the table 40 and is transported byA the liquidmedium to the lower end of the table and onto the screens 41, 42 and 31arranged and constructed and functioning in the same way the screens 26,27 and 28 arel arranged and constructed and function. The splash board44 is also constructed and arranged beyond the end of screen 41 in thesame way as the splash board 30 is ositioned beyond the end of screen26. Al material which passes over screens 41, 42 and 31, drops throughthe chute- 45 into the bin 46 and the mass of A material collecting'inthe bin 46, we designate as the small gravel or one quarter inch or peagravel because screen 41 has rectangular .openingstherein of atransverse dimension of one quarter of an inch and the other dimensionof one half of an inch, and the screens 42 and 31 are formed with likeopenings.

All material passing through screens 4.1, 42 and 31, falls upon thetable 43, and 1s transported b the water along the table 43, which ispitc ed about one half of an inch to the foot, and falls into tanks as47 48, 49 and 50, best shown in plan in Fig. 2, and

in cross sectional elevation in Fig. 3. These tanks are formed in theshape of the frustum of an inverted pyramid and transversely of eachtank is an adjustable baii'le plate as 51, best shown in cross sectionalelevation in Fig. 3. The liquid transporting medium bearing suspendedsand and loam Hows into the tanks as 47 to 50, inclusive, and passingdown and aroundthe baille 51, is free to flow from the tanks over thelower edges thereof as 52, but in passing into and down the tank thelarger heavier particles of material in suspension in the water, drop tothe bottom of the tanks as 47 to 50, inclusive, and only the lightermaterial iiows with the water out over the edges as 52 of thev tanks,this being virtually a settling process. As

Y the heavier particles or Acoarse sand accumulate in the tanks as 47,the level of the water in the tanks raises and in so doing causes ailoat as 53, in a float chamber as 54, to rise. This float is attachedby the two arm lever 55 pivoted at 56 to the rod 57 which extends downthrough a tubular member 58 and through the side of the tank to a lever59, pivoted at 60. Intermediate the pivot 60 and the rod 57 ispositioned a closure 61 for the lower orice of the tank as 47. Whensuicient material has accumulated in a tank yas 47, to cause the floatas 53 to rise, the lever 60 is forced downwardl moving the closure 61from the lower orifice of a tank as 47 and so allowing a certain amountof the collected coarse ysand to How :from the orifice into a receivingcar 62 positioned below the orifice until the level of the water hasbeen reduced sufficiently to allow the ioat 53 to fall enough to againclose the lower orilice of a tank as 47. In practice the orifice at thelower end of a tank as 47 is practically 50 continuously discharging, agreater or less volume of coarse sand.

The transporting medium as water, whichl ows over the edges as 52, runsdownl the inclined slope 63 and into a trough 64. If a contained intrough 64, thenjit flows over the partition 65 into the trough 66. Byref- Y erence to Fig. 2, it will larger volume is 'delivered than maybey scribed. Thesover-iiow from the tanks as 47 to 50, inclusive, inthecase ofthe structure specifically described, would contain not onlythe loam originally raised to the receiving'station R along with thegravel, but would also contain a somewhat large quant-ity of quite finesand. Of course all ot' this ovcriow could be put through another setoftanks identical with 47 to 50, inclusive, as is obvious, ent by thethe demand for tine sand, recover only a part. of the fine sand carriedalong with the overflow from the tanks 47 to 50, inclusive. Applicantsmethod and apparatus for 'doing this, i5 shown particularly,

but applicants governed at presslit 68 is -formed, and in the bottolnofthe trough 66, slit 69 is formed. transporting medium travels alongthe troughs 64 fand 66, a certain amount falls 'through the slits 68 and69. An inclined baile as 70, best vshown in Fig. 3, is placed in trough66, just above the slit 69 in the direction of flow and an inclmedbaffle as 71 is' positioned in trough 64 just above the slit 68, theright hand end of which, as it would be viewed in Fig. 2, being shown inFig. 3.

As the 'liquidf The slits 68 and 69 together with their baf- Y iles aremade of such proportions that the requisite amount or volume of theliquid transporting medium or water is directed therethrough. All of thewater which passes through the slits 68 and 69, bearing' the line sand,drops onto table 72 and then flows into the tank 73, constructed andarranged just as are the tanks 47 to 50, and passing down and below thebaffle 74 thereinows out at the edge 75 and then into the trough 76communicating with trough 68. The vrate of tlow throulgh the tank 73, byreason of the volume delivered thereto, and the position of the baille74 therein, causes the fine particles of sand in the transporting mediumto settle into the bottom onl the lightest suspended material such as0am', y173 just like the tanks 47 to 50, inclusive, is arranged with adischarge apparatus includmg a closure as 61 as shown in connec-v tionwith tank 47 and in operation there is a practically continuous streamof fine sand flowing from the bottom of tank 73 after it once becomesfilled to a certain height with sand.

The transport from tanks 47 to 50, which does not go throughtank 73, andthat portion which does go through tank 73, and overflows into trough76, combine and flow in trough 68 to a settling basin B. This settlingbasin receives the overflow at one end, and preferably at the other endtheretf or at a point quite remote is placed a weir 77 preferablyarranged at such height that the rapidity of flow thereover will be suchthat practically of the tank'73 and' iows over the edge 75. The tank .gmedium overowing obvious. The operation of the centrifugal pump 2necessarily exhausts a very considerableportion of the water lV as itoperates, and as the ground and surface Water flowing into thedepression in which the scow S is situated, may be easily insufficientto constantly supply the pump 2, it might become within a very shortvtime quite `impossible to operate the plant on account of the lack ofwater. Of course if there is an abundant, supply of water flowing intothe depression in which the scow S is situated, then,r it

' may be unnecessary to make use of the settling basin B and return theoverflow water to the depression in which the scour S is situated. It isWell known to those skilled in this art, however, that there isgenerally insufficient-Water in.the usual gravel pit'to constantlysupply a pump discharging thirty five hundred gallons per minuteunlessthe discharge water is again brought back, by

some means, to the inlet end of the pump and it would also be easilyunderstood that' if the gravel contained a very large proportion ofloam, it4 would be quite impossible to return the overflow vwaterrunning through the trough 68sdirectly to the depression in which thescow S is positioned because the Water would soon become so loaded withloam that 'its efficiency as a washing agent for the gravel Whilepassing over the several tables would be very seriously diminished. Itis therefore 'quite 'apparent that the provision for returning the waterfrom the process to the inlet end of thepuinp and the provision of asettling basin to separate the loam from' the water bef-ore arriving atthe inlet of the pump are both most important features of this process,and features which in certain situations would be absolutelyindispensable as a part of the process and without which the processcould not be carried out. It is of course true that incertainsituations, that is, where the gravel. material is drawn from thev bedof a large y iowmgstream, that itwould be unnecessary to make anyVparticular provision for direct- `ing the overflow water back into thestream and of course in such case'no settling basin such as B would benecessaryv and it 1s also true that 1n certain .sltuatlons the nature ofthe gravel might be such that the overliow water coming from the processwould be so free from suspended'matter that it ,could `for taking careof .this` condition.

he led directly into the depression in which the scow S is positioned.Although all of the above suggested methods of operatingl arecontemplated by applicants nevertheless,

applicants have illustrated specifically by Fig. l, that condition whichmight be called the most difficult and the one which requires theextreme of inventive ability to cope with,`

that is, the condition in which the ground and surface water isinsuficient to. constantly supply the pipe 2,? unless water 1s returnedto the inlet, and in which the fine loamy I material is insuch'quantity, thatl the'ivater discharged through the 'trough 68 mustbe run into a settling basin .before being fagain returned to theprocess. It ofcourse, must he realized that the material in a gravelbank is deposited not atall uniformly, so that the proportions of solidand liquid material discharged from the pipe 5, are often such that theliquid is in excessive amount, so mu-ch so, that it interferes with theproper loperation of the process in that too large a' volume of Water orliquid ilowsthrough the tanks as 47 to 50, inclusive, and consequentlythe proper settling of the sand in these tanks is interfered with.Applicants have provided a means Applicants have provided a screen 79back o-f screen 9. 4Thisfsc1-en has openings therein Aof such size thatV only small material will pass therethrough, say nothing larger thanquarter inch material. Back of this screen- 79 is a trough 80. Thematerial delivered through the pipe 5, passes through the grizzly Z,screen 9, and if small enough, through the screen 79 and lands .in thetrough 80. The upper end of the trough 80 is surrounded by. t estructure comprising the side wall lift) 81, the side wall 82, and thetop 83, and an end wall 43, shown in Fig. 4, so that the upper end ofthe trough soon fills and runs over. All water which runs over from theupperend of the trough 80, falls upon the table 25 and so passes throughexactly the same process as has been herei'nbefore described. If toomuch water in proportion to material is being supplied, however, theslide 84 is raised allowing Water and material contained therein intheupper end of the .trough 80 to fiow through the slot 85 and alo'ng thetrough 80. The amount which may be allowed to ow along the trough 80 isregulated ofcourse, by the extent offopening of-slot by the adjust-meritof slide 84, so that a greater or less amount of the water and finematerial which passes through screen 79 maybe allowed to How alongtrough 80, and this amount would be regulated by the necessary amountvofwater which it is desired to-remove from the regulary process. Thematerial which, HowsL along the trough 8O flows into the tank` 86, underand around the baille 87, and then over. the lower edge into the trough88, which perhaps best seen in Fig. 5, communicates by means of aconduit 89 with the trough 68. The passage -ot the liquid transportingmedium through the tank 86 causes the sand and small gravel to bedeposited in the tank 86 and when de-V sired this material is droppedonto the table by an operation of lever 90 which causes an orifice inthe bottom of the tank. to be opened. By the means just described, thequantity of water when too great in amount, is decreased, butneverth'eless the salable material transported by the water is removedby a settling tank as 86 and then returned to the process at a properpoint, 'sop as best shown in Fig.3, is constructed with the discharo'edmaterial sloping sides and with an orifice at its lower end closed by aslide as "96 operated by a rod as 97, so that a car may be positionedunderneath a bin and then an operator by operation of rod 97 may move aslide as 96A in the bottom of a bin as 24, and cause the collectedmaterial therein to run in to the car. As the tanks 47 to 50, inclusive,are practically continuously discharging while the plant is inoperation, cars are always positioned underneath these tanks to receiveand this is also true of the tank 73. Y

From the hereinbefore given description, it will now be understood thatapplicants process provides a method whereby the gravel of the ordinarygravel bank may be elevated to a receiving station on a structure a-ndthen'without further power being applied thereto or expended in any way,it may besortcd into several grades of clean gravel and of; clean sand,and the sorted material delivered4 directly into transportingr vehicles.i

Although in describing our improved process, for the purposes ofillustration, we have specified a particular classification of thegravel material, as into one and one half inch, three quarter inch, andone quarter inch gravel, and `coarse sand and fine sand, and in ordr toaccomplish this classification, -we have specified particular specificdimensions of screens and particular specific angles of inclinationoftables and screens, nevertheless, we'desire to have it understood thatthe process is applicable for the classilication of gravel material intoa greater number of rades and sizes varying between different limits andthe screen inclinations and the tablev inclinations are not to beconthoroughly washing a mass sidered as the only ones possible as thesemay be varied depending upon the specilic volume of transporting mediumdelivered at the receiving station and the usual proportions of solidmaterial and medium in that which is delivered and readiness of flow ofthe material.

Although we have particularly described one particular physicalembodiment of means for practicing our process, nevertheless, we desireto have it understood that this means is merely illustrative and doesnot exhaustthc possible physical embodiments of means by which theprinciplesl of our process may be practiced.

lVhat we claim as new and desire to secure by Letters Patent of theUnited States, is:

1. Theprocess of sorting a-mass of .heterogeneous material whichconsists in elevating the material mixed with a liquid, discharging thematerial and liquid, separating oversize material, thoroughly washingthe oversize material with the discharged liquid, combining the entirewashings with the main mass and then dry screening the oversizematerialto remove any possible proper size material wanted.

2. The process of sorting a mass of heterof geneous material whichconsists in elevating the material mixed with ing the material andliquid, segregating and thoroughly fwashing oversize material, theniowing the main mass and the washings downward by gravity and se aratingand' thoroughly washinga mass oi upper limit material.

, 3. The process of sorting a mass of heterogeneous material lwhichconsists in elevating the material mixed with ing the material andliquid, segregating and thoroughly' washing oversize material, thenflowing the main mass downwardly, by gravit separating andthoroughlywashing a mass of upper limit material, then flowing theresidue and the washings downwardly by gravity and separating and'thoroughly washing an intermediate lilit material.

4. Thetprocess of sorting a mass of heterogeneous material whichconsists in elevating the material mixed with a liquid, discharging thematerial and liquid, segregating and a liquid, discharga liquid,diseharg`A and the washings y thoroughly washing oversize material, thenflowing the main mass and the washings downwardly. by gravity,separating and of upper limit material, then owingthe residue and thelwashings downwardly by gravity and separating and thoroughly washing anintermediate'limit material, then flowing'the remaining residue andwashings by gravity and separating washing a lower limit material andthen treating the last remaining residue and the downwardly d thoroughlydownwardly by gravity, separating 'and thoroughly washing a mass ofupper limit material, then lowing the residue and the washingsdownwardly by gravity and separating and thoroughly washing anintermediate limit material, then flowing the remaining residue andwashings downwardly by separating and thoroughl washing a lower limitmaterial, thenlowing the remainingresidue and washings downwardl bygravity'and separating and thoroug ry washing a lower limit material,then separating the coarser particles from the vlast obtained l residueand last washings by rapid' settling.

6. The process of .sorting a mass of heterogeneous material whichconsists .in elevating the material mixed with a liquid, discharging thematerial and liquid, segregating and thoroughly washing oversizematerial, then flowing the main mass'the washings downward] by gravity,separatingand thoroughly was ing a mass of upper limit material, thenflowing the .residue and thev washings downwardly by gravity andseparating and thoroughly washingan intermediate limit material, theniowing the remaining residue and washii'igs downwardly. by gravity andseparating and thoroughly washing a lower limit material, then flowingthe remaining residue .and washings downwardly by gravity and separatingand thoroughly washing a lower limit material, then separating thecoarer particles from ythe-lastl obtained residue and last washings byrapid settling, then separating finer particles from the residue by afurther not so ra id settling.

l. The process of sorting a mass of heterogeneous material whichconsists in elevating the material mixed with a liquid, discharging thematerial and liquid, segregating and thoroughly washing` oversizematerial, then flowing the main mass andthe washings downwardly bygravity, `separating and thoroughly washinga mass. of up-y per limitmaterial, then flowing the residueand the washings downwardly by gravityand separating` and thoroughly w g an intermediate limit material, thenflowing the remaining residue and washings downwardly ing a lowerlimitmaterial, then avity and by ravity and se arating and thoro h1 vmi P iwfing the remaining residue and washings downwardly by gravity andseparating and thoroughly washing a lower limit material, thenseparating the coarser particles from the last obtained residue and lastwashings by rapid settling, then separating finer particles from theresidue by a further not so rapid settling, then allowing the liquidcontaining the ightest material to become so quiescent that suchlightest material substantially -all settles and conducting thesupernatant liquid to material to be sorted to be againelevated withsaid material.

8. The process of sorting -a mass or hetero- .geneous material Vwhichconsists in elevating the same. with a liquid as a transporting medium,separating part of the liquid and finer material from the rest, separatithe finer material so separated from the liquid and then combining thisliner material with the original mass of material and liquid from whichit was first separated.

9. In a gravel sorter, in combination: a

discharge pipe; means for discharging mixed f beneath the grizzly andthe first said screen and the discharge en d 'of 'the ipe said screenbeing inclined to the h orizontal whereby gravel will roll downwardlythere-v 10. In a gravel :"s'orter, in combination: a discharge pipe;means ,for discharging mixed water and gravel therefrom; a grizzlyvpositioned adjacent the discharge end of the pipe and at an angleless'than a ri/ghtv angle to the longitudinal centerline of the pipe; avertical screen having circular open-` ings therein adjacent the grizzlybut more remote from the .pipe but .ii the range of the dischal from thepipe; .another screen having Asq re openings therein positioned beneaththe rizfzly, the rst saidscreen and the discliarge end of the ipe, saidscreen 'being inclined to the orizontal wherebyh gravelwill rolldownwardly thereon and pivoted bales having their free ends adjacent thelast mentioned screen of such weight that 'material rolling down thelast miioned' screen will be temporarily arre FREDERICK-1w. SCHMIDT.WILLIAM M. GREEN. l

